This week marks the second anniversary of an event that shook the financial industry to its core. In her newly released book, 'The Weekend that Changed Wall Street,' CNBC anchor Maria Bartiromo gives an insider's look at the fateful days surrounding the fall of Lehman Brothers.

Lehman Brothers Holdings, the once great Wall Street firm that went bankrupt at the height of the financial crisis, says it will have to pour hundreds of millions of dollars into two struggling units to avoid failures that could cost the investment bank billions.